U.S. patent application number 11/492260 was filed with the patent office on 2008-01-31 for geothermal heat loop installation.
Invention is credited to Joseph W. Stevens.
Application Number | 20080023228 11/492260 |
Document ID | / |
Family ID | 38985001 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080023228 |
Kind Code |
A1 |
Stevens; Joseph W. |
January 31, 2008 |
Geothermal heat loop installation
Abstract
Methods and apparatuses associated with a rotary driven well
drilling rig. One method includes providing a rig having: an
erectable mast; a head drive unit for rotatably driving drill pipes
into a surface; a pumping unit to deliver a fluid through a drill
pipe secured to the head drive, the fluid being forced out a bottom
end of the drill pipe and up to the surface along the outside of
the drill pipe during a borehole drilling operation; and a deck
unit pivotally mounted on a turret attached to a set of tracks.
This method embodiment includes, while the rig is in a first
location, performing a first borehole drilling operation to form a
first borehole at a second location; and performing a second
borehole drilling operation to form a second borehole at a third
location while the rig remains in the first location.
Inventors: |
Stevens; Joseph W.; (Mound,
MN) |
Correspondence
Address: |
BROOKS, CAMERON & HUEBSCH , PLLC
1221 NICOLLET AVENUE , SUITE 500
MINNEAPOLIS
MN
55403
US
|
Family ID: |
38985001 |
Appl. No.: |
11/492260 |
Filed: |
July 25, 2006 |
Current U.S.
Class: |
175/57 ;
175/162 |
Current CPC
Class: |
F24T 10/00 20180501;
F24T 2010/53 20180501; F24T 10/10 20180501; E21B 15/003 20130101;
Y02E 10/10 20130101; E21B 7/02 20130101 |
Class at
Publication: |
175/57 ;
175/162 |
International
Class: |
E21B 19/08 20060101
E21B019/08 |
Claims
1. A method for geothermal heat loop installation, comprising:
providing a rotary driven well drilling rig, the drilling rig
comprising: an erectable mast; a head drive unit capable of linear
movement along the mast for rotatably driving drill pipes into a
surface; a pumping unit to deliver a fluid through a drill pipe
secured to the head drive, the fluid being forced out a bottom end
of the drill pipe and up to the surface along the outside of the
drill pipe during a borehole drilling operation; and a deck unit
pivotally mounted on a turret attached to a set of tracks, the deck
unit supporting the mast; while the rig is in a first location,
performing a first borehole drilling operation to form a first
borehole at a second location; and performing a second borehole
drilling operation to form a second borehole at a third location
while the rig remains in the first location.
2. The method of claim 1, wherein the method includes: positioning
the turret at the first location; performing the first borehole
drilling operation such that the second location is a radial
distance from the first location; and performing the second
borehole drilling operation such that the third location is
different from the second location and is located the radial
distance from the first location.
3. The method of claim 2, wherein performing the second borehole
drilling operation includes rotating the deck unit on the turret
without moving the set of tracks.
4. The method of claim 3, wherein rotating the deck unit includes
rotating the deck unit while the mast is in an erected
position.
5. The method of claim 1, wherein the method includes performing at
least four borehole drilling operations to form the first and the
second, and a third and a fourth borehole while the rig remains in
the first location such that the first, second, third, and fourth
boreholes are located the radial distance from the first
location.
6. The method of claim 5, wherein the method includes performing
the at least four borehole drilling operations such that the first,
second, third, and fourth boreholes are evenly spaced
circumferentially around the first location.
7. The method of claim 5, wherein the method includes performing
each of the at least four borehole drilling operations such that
the first, second, third, and fourth boreholes are each angled
radially outward.
8. The method of claim 1, wherein performing a borehole drilling
operation comprises: securing an attachment end of a first drill
pipe to the head drive unit, the first drill pipe attachable to a
drill bit; activating the pumping unit to deliver the fluid through
the first drill pipe and the drill bit; activating the head drive
unit to rotate the first drill pipe and move the unit along the
mast to force the drill bit into the surface; and deactivating the
head drive unit and pumping unit and detaching the head drive unit
from the first drill pipe when the head drive unit reaches a
lowermost position.
9. The method of claim 8, wherein performing a borehole drilling
operation further comprises: raising the head drive unit and
securing a second drill pipe to the attachment end of the first
drill pipe and to the head drive unit to form a drill string;
reactivating the pumping unit to deliver the fluid through the
string; reactivating the head drive unit to rotate the string;
lowering the string further into the surface until the drill head
drive unit reaches the lowermost position or until the string
reaches a desired depth below the surface; and adding additional
drill pipes to the drill string if the desired depth has not been
reached.
10. The method of claim 1, wherein performing at least one of the
borehole drilling operations includes drilling a borehole at an
angle less than 90 degrees with respect to the surface.
11. The method of claim 1, wherein performing each of the borehole
drilling operations includes drilling boreholes having a diameter
of about four inches to a depth of about 200 feet.
12. A rotary driven well drilling apparatus for installation of
geothermal loops comprising: a deck having an erectable mast
attached thereto; a head drive unit to rotatably drive a number of
drill pipes into a ground surface in order to form a geothermal
borehole capable of housing a geothermal loop, the number of drill
pipes forming a drill pipe string, and the head drive unit being
attached to the erectable mast and capable of linear movement
thereon; a pumping unit to deliver a fluid through the drill pipes
during a drilling operation, the fluid being delivered through the
inside of the drill pipes at a top end of the string and flowing
upward toward the ground surface on the outside of the drill string
after passing through a drill bit of the drill string; and wherein
the deck is mounted on a turret attached to a set of tracks to
drill a number of geothermal boreholes.
13. The apparatus of claim 12, wherein the apparatus includes a
carousel attached to the mast for holding the number of drill pipes
and wherein the head drive pivots to remove drill pipes from the
carousel and return drill pipes to the carousel during the drilling
operation.
14. The apparatus of claim 12, wherein the apparatus is configured
such that the mast can remain in an erected position while the deck
is rotated on the turret.
15. The apparatus of claim 12, wherein the turret includes an
opening having a conduit passing therethrough, the conduit capable
of attachment to a hose to provide a fluid source to the pumping
unit.
16. The apparatus of claim 12, wherein the apparatus is configured
such that the apparatus exerts a pressure of less than 20 pounds
per square inch (psi) upon the ground surface.
17. The apparatus of claim 12, wherein the apparatus includes a mud
pan attached to the apparatus to receive cuttings from the drilling
operation.
18. The apparatus of claim 12, wherein the turret is positioned at
a first location relative to the ground surface to drill a first
geothermal borehole at a second location, wherein the second
location is a radial distance from the turret, and wherein the
turret is rotatable to rotate the deck while the turret remains at
the first location to drill a second geothermal borehole at a third
location, the third location being different than the second
location and located the radial distance from the first
location.
19. The apparatus of claim 12, wherein the deck is configured to
rotate while the set of tracks remain stationary to drill the
number of geothermal boreholes a radial distance from the
turret.
20. A rotary driven well drilling apparatus for installation of
geothermal loops comprising: a deck having an erectable mast
attached thereto; a head drive unit movably attached to the mast
and capable of linear movement thereon to rotatably drive a number
of drill pipes into a ground surface by using a drive shaft having
threads on a lower end for removably engaging threads on the number
of drill pipes in a drill string in order to form geothermal
boreholes; a pumping unit to deliver a drilling fluid to the head
drive unit such that the drilling fluid passes through the lower
end of the drive shaft and down through a drill bit end of the
drill string during a drilling operation; and wherein the deck is
rotatably mounted on a turret attached to a set of caterpillar
tracks to perform a plurality of drilling operations at a first
location of the turret relative to the ground surface in order to
drill a plurality of geothermal boreholes a radial distance from
the first location while the turret remains at the first
location.
21. The apparatus of claim 20, wherein deck is configured to rotate
on the turret through 360 degrees.
22. The apparatus of claim 20, wherein the drilling fluid is
delivered to the head drive via a conduit passing between the
caterpillar tracks and up through the turret.
23. The apparatus of claim 20, wherein the apparatus includes a
number of jacks attached to the deck and removably engagable with
the ground surface during drilling operations.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to drilling rigs
and, more particularly, to rotary driven well drilling rigs for
geothermal heat loop installation.
BACKGROUND
[0002] Rotary driven well drilling rigs can be used to create
boreholes of various sizes for a variety of purposes. For example,
such rotary driven rigs can be used to form boreholes for
geothermal heat loop installation. Geothermal heat loop systems use
the earth as a constant source of heat to be extracted by a heat
pump. Extracting heat from the ground, which can have a near
constant temperature, can be more efficient than extracting heat
from the air, which can be subject to extreme temperature
variations. Such geothermal systems can reduce heating/cooling
costs and are environmentally friendly by reducing the use of
fossil fuels to heat/cool homes and buildings, for example.
[0003] Geothermal heat loops can be installed to heat and/or cool
homes, schools, churches, commercial buildings, etc. The heat loop
installation process can involve drilling a number of boreholes
into which the loops are placed. The boreholes are often drilled
using wet/air rotary drill rigs. Many current rotary well drilling
rigs consist of boring machinery mounted atop large trucks that can
weigh 15 tons or more exerting a ground contact pressure of 45-50
pounds per square inch (psi).
[0004] Operating current rotary well drilling rigs can be damaging
to property. The heavy truck mounted drilling rigs can leave large
piles of cuttings and muddy streams of run-off water along with
numerous tire ruts throughout a drilling area. The damage can be
exacerbated as current drilling rigs often drill a single borehole
while having to move the entire truck to another location to drill
subsequent boreholes.
[0005] As such, it can be especially undesirable to use current
wet/air rotary drilling rigs in order to drill boreholes in areas
where landscaping can be important, such as in residential areas or
around school playgrounds, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1A is a side view of a rotary driven well drilling rig
according to an embodiment of the present disclosure.
[0007] FIG. 1B is a rear view of the rotary driven well drilling
rig shown in FIG. 1A.
[0008] FIG. 2 is an overhead view showing borehole placement
according to an embodiment of the present disclosure.
[0009] FIG. 3 is an overhead view showing borehole placement
according to another embodiment of the present disclosure.
[0010] FIG. 4A illustrates more detail of a turret embodiment
having a conduit therethrough according to the present
disclosure.
[0011] FIG. 4B illustrates an overhead view of the embodiment shown
in FIG. 4A.
[0012] FIG. 5 illustrates a method for geothermal borehole
installation according to an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0013] The present disclosure includes various methods and devices
for geothermal heat loop installation. One method embodiment
includes providing a rotary driven well drilling rig that comprises
an erectable mast, a head drive unit capable of linear movement
along the mast for rotatably driving drill pipes into a surface, a
pumping unit to deliver a fluid through a drill pipe secured to the
head drive, the fluid being forced out a bottom end of the drill
pipe and up to the surface along the outside of the drill pipe
during a borehole drilling operation, and a deck unit pivotally
mounted on a turret attached to a set of tracks, the deck unit
supporting the mast. The method further includes, while the rig is
in a first location, performing a first borehole drilling operation
to form a first borehole at a second location, and performing a
second borehole drilling operation to form a second borehole at a
third location while the rig remains in the first location.
[0014] FIGS. 1A and 1B are a side view and a rear view,
respectively, of a rotary driven well drilling rig 100 according to
an embodiment of the present disclosure. As shown in the embodiment
illustrated in FIG. 1A, drill rig 100 includes a deck 130 having a
mast 110 attached thereto. Mast 110 can be moved between a
horizontal position and a vertical position via hydraulic cylinder
132. In various embodiments of the present disclosure, the mast 110
is moved to the horizontal position for transporting rig 100 from
one drilling site to another. The mast 100 can be moved to a
vertical position as shown in FIGS. 1A and 1B in order to drill
vertical boreholes or to various positions between the horizontal
and vertical positions in order to drill boreholes at angles less
than vertical, e.g., less than 90 degrees with respect to the
ground surface. As discussed below, in various embodiments, the
drill rig 100 is configured such that mast 110 may remain in the
vertical or a substantially vertical position during consecutive
borehole drilling operations.
[0015] The drill rig 100 includes a head drive unit 120 that is
movably attached to the mast 110. The head drive 120 can move
linearly along mast 110 and can pivot longitudinally around mast
110 in order to retrieve drill pipes 128 from a drill pipe carousel
126 during a borehole drilling operation. The embodiment
illustrated in FIGS. 1A and 1B show a vertical drill pipe carousel
126. However, embodiments are not limited to a vertical carousel
attached to mast 110. For example, in some embodiments, the drill
pipes 128 can be stacked in an elongated storage tray attached to
the deck 130 and can be moved between the drill shaft 124 and the
storage tray by using a cable or other suitable hoisting device as
are known in the art.
[0016] The head drive 120 can be moved upward and downward via a
pair of chains or other means known in the art. The head drive unit
120 includes a drive shaft 124 having male threads at a lower end
125. During a borehole drilling operation, drive shaft 124 is
rotatably secured to a drill pipe segment 128 by mating with female
threads (not shown) at one end of a drill pipe 128. Embodiments are
not limited to this example.
[0017] As will be understood by those of ordinary skill in the art,
each drill pipe 128 can have a female threaded end and a male
threaded end. The female end can be secured to drive shaft 124 or
to a male end of another drill pipe to form a drill string. The
lowermost drill pipe 128 in a drill string can have a cutting bit
(not shown) attached thereto, as the same are known in the art. In
operation, the head drive unit 120 rotates drive shaft 124 and is
moved downward along mast 110 in order to rotatably drive a drill
string into the ground surface to form a borehole.
[0018] Drill rig 100 also includes a pumping unit 136 ("mud pump")
on deck 130. The pumping unit 136 delivers drilling fluid to the
head drive 120 via a conduit, such as a hose, from the pumping unit
136 to a connector 122 on head drive 120. The drilling fluid can be
bentonite mixture such as Quick Gel or a liquid polymer such as EZ
Mud, among various other drilling fluids. The drilling fluid is
delivered through the inside of drive shaft 124 and down through
its lower end. The drilling fluid passes from the drive shaft 124
down through the insides of the drill pipes 128 in a drill string
and down through the bit end of the first drill pipe 128 in the
string. The pressure from pumping unit 136 forces the drilling
fluid out of the bit end of the string such that the drill
"cuttings" flow up to the surface of the borehole on the outside of
the drill string.
[0019] In the embodiment illustrated in FIGS. 1A and 1B, the deck
unit 130 includes a mud pan 131 attached thereto. In various
embodiments, the mud pan 131 can store drill cuttings produced
during borehole drilling operations in order to maintain an area
around drill rig 100 substantially free of the cuttings.
[0020] As shown in FIGS. 1A and 11B, in various embodiments of the
present disclosure, the deck unit 130 is mounted on a turret 140
attached to a set of tracks 150, e.g., caterpillar tracks, to drill
a number of geothermal boreholes as further discussed in detail
below in connection with FIGS. 2 and 3.
[0021] In various embodiments, and as discussed below in connection
with FIG. 4, the drill rig 100 can be configured such that air or
fluid can be delivered via a conduit through the turret 140. For
example, in various embodiments, the turret 140 includes an opening
through which one or more hoses can pass in order to deliver air
and/or water/and or drilling fluid to/from various components of
drill rig 100, e.g., mud pump 136, head drive 120, hydraulic pumps
137, etc. Configuring drill rig 100 in this manner can reduce
and/or prevent occurrences of hoses being twisted and/or damaged
during geothermal borehole drilling operations as discussed
herein.
[0022] In various embodiments, the tracks 150 are composed of metal
and/or rubber and can be configured such that drill rig 100 exerts
a reduced pressure on the ground surface as compared to
conventional geothermal borehole drilling rigs, e.g., truck mounted
drilling rigs. In some embodiments, the tracks 150 of track mounted
drill rig 100 are configured such that a pressure less than 20
pounds per square inch (psi) is exerted on the ground surface. In
one embodiment, the tracks 150 are configured to exert a ground
surface pressure of less than 10 psi. In another embodiment, the
tracks 150 are configured to exert a ground surface pressure of not
more than 5 psi. In various embodiments, the tracks 150 can also
provide reduced damage to landscaping upon moving drill rig 100 at
a drilling site as compared to truck mounted drill rigs that can
often create large tire ruts due to a higher exerted ground
pressure that can be 45 psi or more.
[0023] In various embodiments, the drill rig 100 is configured to
drill a number of geothermal boreholes by being positioned at a
first location, e.g., the turret 140 can be positioned at the first
location to drill a first borehole located at a second location,
e.g., a location that is a radial distance from the turret 140. In
such embodiments, the deck 130 can be pivoted on turret 140 while
the turret 140 remains at the first location, e.g., at a stationary
location relative to the ground surface, in order to drill a second
borehole at a third location that is different than the second
location and is located the radial distance from the first
location. In various embodiments, the deck 130 is configured to
rotate while the set of tracks 150 remain stationary. Drilling a
number of boreholes without moving tracks 150 can reduce the amount
of damage to various landscaping features at a geothermal heat loop
installation site, for example.
[0024] The deck 130 also includes an operator cab 138 attached to a
front end from which an operator can perform various operations
such as positioning the tracks 150 at a location to drill a number
of boreholes with drill rig 100. The drill rig 100 further
comprises a fuel tank 139 and an engine 135 located adjacent to the
cab 138 on deck 130. In the embodiment shown in FIGS. 1A and 1B,
the fuel tank 139 and mud pump 136 are mounted beneath the deck and
below the engine 135. The engine 135 is attached to a number of
hydraulic pumps 137 for providing power to hydraulic components of
the rig 100 such as the hydraulic cylinder 132, the outriggers 155,
the head drive unit 120, the turret 140, the tracks 150, etc.
Electrical, petroleum, and hydraulic power systems can all be
employed individually or in combination. Embodiments of the present
disclosure are not limited to the example given here.
[0025] As illustrated in the embodiment shown in FIGS. 1A and 1B,
the cab 138, fuel tank 139, engine 135, mud pump 136, and hydraulic
pumps 137 are positioned at the end of deck 130 opposite the mast
110. The placement of these elements near the front end of deck 130
acts to balance the weight of the back end when the mast 110 is in
an erected position. In various embodiments, the placement of these
elements provides for the ability to rotate deck 130 on turret 140
while the mast 110 remains in a vertical or nearly vertical erected
position. In this manner, various embodiments of drill rig 100 can
drill consecutive boreholes in a circumference around turret 140
without lowering mast 110 and/or without moving rig 100 between
consecutive borehole drilling operations.
[0026] The deck 130 in the embodiment shown in FIGS. 1A and 1B
further includes a number of jacks 155, or outriggers, attached to
the deck 130 and removably engagable with the ground surface during
drilling operations. The jacks 155 can be used to stabilize
drilling rig 100 during drilling and can be used to level drilling
rig 100 when operating on uneven terrain, e.g., on an inclined
surface.
[0027] The drill rig 100 also includes a control panel 134, as
shown in FIG. 1B, comprising various gauges and controls for
operating drill rig 100 to perform and/or monitor borehole drilling
operations. The controls can be operated from an operator platform
141. Control panel 134 can include controls for erecting mast 110,
raising/lowering head drive 120, lowering/raising jacks 155,
operating pumping unit 136, and operating drive shaft 124 among
various other operating controls for use in drilling boreholes with
drill rig 100. For example, in this embodiment, the control panel
134 includes controls 133 which can be used to rotate the deck 130
and/or to operate tracks 150. In various embodiments and as shown
in FIG. 1B, the control panel 134 is located at the rear end of
deck 130 allowing an operator of control panel 134 to view the
borehole drilling operation from the operator platform 141 while
operating the controls. However, embodiments are not limited to a
location of control panel 134 at the rear of deck 130.
[0028] Furthermore, in some embodiments, one or more of the
controls of control panel 134, e.g., controls 133, may be disabled
during borehole drilling operations. For instance, in some
embodiments the controls 133 can be disabled, e.g., from operator
cab 138, in order to prevent movement of the tracks 150 and/or deck
130 during borehole drilling. This can prevent damage to the
various drilling rig components, e.g., the head drive 128, the
drive shaft 124, etc., that can result from moving the tracks
and/or deck during borehole drilling. In some embodiments, the
control 133 for moving the tracks can be disabled while the control
133 for rotating the deck remains enabled. In such embodiments, an
operator of control panel 134 may control rotation of the deck 130
on turret 140 but may not control movement of the tracks 150. This
can allow an operator of control panel 134 to rotate the deck 130
to subsequent borehole drilling locations, which can facilitate
accurate rotational positioning since the operator can view the
positioning of the rig as the deck rotates.
[0029] In various method embodiments of the present disclosure,
performing a borehole drilling operation by using drill rig 100
includes securing an attachment end (female threaded) of a first
drill pipe 128 to the head drive unit 120 via a lower end 125 (male
threaded) of drive shaft 124. The first drill pipe includes a drill
bit (not shown) at its other end. The method includes activating
the mud pump 136 to deliver the drilling fluid through the first
drill pipe 128 and drill bit and activating the head drive unit 120
to rotate the first drill pipe 128 and to move the head drive 120
down along mast 110 to force the drill bit into the ground surface.
The method includes deactivating the head drive unit 120 and mud
pump 136 and detaching the head drive 120 from the first drill pipe
128 when the first drill pipe has penetrated into the surface
sufficiently and a next drill pipe 128 is to be added to the drill
string to continue drilling to a greater depth.
[0030] In various method embodiments, when the drilling depth is to
be continued, the method further includes raising the head drive
120 from a lowermost position and securing a second drill pipe 128
to the attachment end of the first drill pipe 128, e.g., the
current uppermost drill pipe of the drill string, and to the head
drive 120 to thereby extend the drill string and continue drilling
into the surface. The method includes reactivating the mud pump 136
to deliver drilling fluid through the drill string and reactivating
the head drive 120 to rotate the drill string. The method further
includes lowering the drill string further into the surface until
the drill head drive 120 reaches the lowermost position or until
the string reaches a desired depth below the surface, e.g., an
appropriate depth for a geothermal heat loop such as 150-250 feet.
The method includes adding additional drill pipes 128 to the drill
string if the desired depth has not been reached.
[0031] FIG. 2 is an overhead view showing borehole placement
according to an embodiment of the present disclosure. The
embodiment illustrated in FIG. 2 shows a number of borehole
locations 280-1, 280-2, . . . 280-N each located a radial distance
285 from turret 240 of drill rig 200, which is positioned over a
fixed location 284 of the drilling surface, e.g., the ground
surface. The designator "N" is used to indicate that embodiments
can include a number of borehole locations. In this embodiment, the
boreholes 280-1 to 280-N are evenly spaced around a circumference
282 the radial distance 285 from turret 240, however embodiments
are not limited to evenly spaced boreholes or to boreholes spaced
circumferentially around a turret, e.g., turret 240.
[0032] In the embodiment illustrated in FIG. 2, the number of
boreholes 280-1 to 280-N can be drilled by rotating deck 230 on
turret 240 while the turret 240 remains positioned over fixed
location 284, e.g., a center of the turret remains stationary
relative to the ground surface. In various embodiments, the deck
230 is configured to rotate through 360 degrees. Also, in various
embodiments and as shown in FIGS. 4A and 4B, the turret of rig 200
can be configured such that one or more conduits, e.g., hoses, can
pass through the turret to reduce/prevent twisting and/or damage to
the hoses during drilling operations. In various embodiments, the
number of boreholes 280-1 to 280-N can be drilled while the tracks
250 remain stationary with respect to the ground surface.
[0033] By way of example and not by way of limitation, in various
embodiments, the boreholes 280-1 to 280-N have a diameter of 4
inches and are drilled to a depth of 200 feet. Embodiments of the
present disclosure may include drilling boreholes which have
diameters greater or less than 4 inches and/or depths greater or
less than 200 feet. In various embodiments, one or more of the
boreholes 280-1 to 280-1 are geothermal boreholes into which
geothermal heat loops can be placed. In some such embodiments, the
boreholes 280-1 to 280-N around circumference 282 are spaced apart
by at least 8 feet. For example, in one embodiment, the boreholes
are evenly spaced by about 12 feet around a 60 foot circumference.
In such an embodiment, the boreholes are a radial distance (r) 285
of about 10 feet from the center of the circumference, e.g.,
location 284 centered with the turret 240. The spacing between the
boreholes can depend on various factors including the depth of the
boreholes, drilling conditions, and geological conditions, among
other factors.
[0034] FIG. 3 is an overhead view showing borehole placement
according to another embodiment of the present disclosure. The
embodiment illustrated in FIG. 3 shows a number of geothermal
borehole locations 380-1, 380-2, . . . 380-N each located a radial
distance (r) 385 from turret 340 of drill rig 300, which is
positioned over a fixed location 384 of the drilling surface, e.g.,
the ground surface. The designator "N" is used to indicate that
embodiments can include a number of borehole locations.
[0035] The embodiment illustrated in FIG. 3 is similar to the
embodiment illustrated in FIG. 2. In this embodiment, the
geothermal boreholes 380-1 to 380-N are each angled radially
outward from the turret 340. Angling the entry points of boreholes
380-1 to 380-N into the ground surface may allow the boreholes to
be spaced more closely together in order to reduce/prevent
geothermal heat loops placed in those boreholes from overly
competing for ground thermal energy. That is, angling the boreholes
380-1 to 380-N can mitigate the competition for ground thermal
energy between adjacent geothermal heat loops.
[0036] In some embodiments, the boreholes 380-1 to 380-N are angled
outward by at least 15 degrees which can reduce heat exchange
between adjacent geothermal boreholes, e.g., 380-1 and 380-2, as
the distance between the adjacent boreholes increases with drilling
depth. As shown in FIG. 3, in one embodiment, 8 geothermal
boreholes can be drilled around a circumference 382. In this
embodiment, the 8 boreholes are evenly spaced around a
circumference 382 of about 75 feet, by a distance (d) of about 9
feet. In this example, each of the 8 boreholes are placed a radial
distance (r) 385 of about 12 feet from the center of the
circumference, e.g., location 384 centered with the turret 340.
Embodiments are not limited the number of geothermal boreholes or
angles at which they are drilled. More or fewer geothermal
boreholes can be radially spaced around the circumference according
to various embodiments.
[0037] As in the embodiment shown in FIG. 2, in the embodiment
illustrated in FIG. 3, the number of boreholes 380-1 to 380-N can
be drilled by rotating deck 330 on turret 340 while the turret 340
remains positioned over fixed location 384. In various embodiments,
the deck 330 is configured to rotate through 360 degrees. In some
embodiments the deck 330 is configured to rotate less than 360
degrees. Also, in various embodiments and as discussed in
connection with FIGS. 4A and 4B, the turret of rig 300 can be
configured such that one or more conduits, e.g., hoses, can pass
through the turret to reduce/prevent twisting and/or damage to the
hoses during drilling operations. In various embodiments, the
number of boreholes 380-1 to 380-N can be drilled while the tracks
350 remain stationary with respect to the ground surface. That is,
the tracks 350 do not have to be moved while rotating the deck 330
for performing the various borehole drilling operations 380-1 to
380-N.
[0038] By way of example and not by way of limitation, in various
embodiments, the boreholes 380-1 to 380-N have a diameter of 4
inches and are drilled to a depth of 200 feet. Embodiments of the
present disclosure may include drilling boreholes which have
diameters greater or less than 4 inches and/or depths greater or
less than 200 feet.
[0039] FIGS. 4A and 4B illustrate more detail of a turret
embodiment 400 having a conduit 421 therethrough according to the
present disclosure. FIG. 4B illustrates an overhead view of the
embodiment shown in FIG. 4A. In this embodiment, the conduit 421
can be an enclosed passageway through which one or more hoses can
pass to deliver drilling fluid to a head drive unit, e.g., head
drive unit 120 as shown in FIGS. 1A and 1B, during borehole
drilling operations. Similarly, electrical wiring can pass through
conduit 421. As shown in the embodiment illustrated in FIGS. 4A and
4B, the conduit 421 passes between the tracks 450 and up through an
opening in the turret 440 and the deck 430. As one of ordinary
skill in the art will appreciate, the conduit 421 can be attached
or connected to the turret 440 by suitable attachment means, e.g.,
rods 449 in FIGS. 4A and 4B.
[0040] According to various embodiments, each end of the conduit
421 can include mating attachments 423 and 447, e.g., quick
couplers, such that a hose can be connected thereto. For example, a
hose can be attached to mating attachment 447 and connected on to a
pumping unit of the drill rig, e.g., mud pump 136 as shown in FIG.
1A, for further connection and pumping action to a head drive
connector, e.g., 122 as shown if FIG. 1A.
[0041] In various embodiments, the conduit 421 can include one or
more bends 442 and 443 which can include a swivel 448. As an
example, the swivel 428 can be a ninety degree elbow swivel which
can reduce or prevent damage to the hose 421 by preventing it from
twisting and/or knotting as the deck rotates on turret 440 during
borehole drilling operations as described herein. In the embodiment
illustrated in FIGS. 4A and 4B, the end of conduit 421 that passes
between tracks 450 includes a mating attachment 423, e.g., a quick
coupler, for releasably attaching to a fluid source, e.g., a water
tank, via another conduit such as another hose segment, for
example.
[0042] FIG. 5 illustrates a method for geothermal borehole
installation according to an embodiment of the present disclosure.
At block 510 the method includes providing a rotary driven well
drilling rig, e.g., rig 100 of FIGS. 1A and 1B, to a first
location, e.g. location 284 as shown in FIG. 2.
[0043] As illustrated in block 520 of the embodiment shown in FIG.
5, the method includes, while the rig is in the first location,
performing a first borehole drilling operation to form a first
borehole at a second location, e.g., location 280-1 of FIG. 2 or
380-1 of FIG. 3, a radial distance, e.g., 285 of FIG. 2 or 385 of
FIG. 3, from the first location, e.g., location 284 of FIG. 2 or
384 of FIG. 3. Using the embodiment of FIG. 2 as an example, the
method can include forming a first borehole 280-1 while the rig 200
is in a first location, e.g., rig 200 is positioned such that
turret 240 is located over location 284, such that the first
borehole 280-1 is positioned a radial distance 285 from turret 240
and/or location 284. That is, the center of turret 240 can remain
stationary relative to the ground surface location 284 between
subsequent borehole drilling operations.
[0044] In the method embodiment illustrated in FIG. 5 at block 530,
the method includes performing a second borehole drilling operation
to form a second borehole at a third location without having to
move the tracks, e.g., tracks 350 of FIG. 3, while the drill rig
remains in the first location. As described herein, the third
location, e.g., location 380-2 of FIG. 3, is different from the
second location and can be located the same radial distance from
the first location. As another example, using the embodiment of
FIG. 2, the method can include forming a second borehole at a third
location, e.g., 280-2, without having to move the tracks 250, while
the drill rig 200 remains at the first location 284. As such,
borehole 280-2 can thus be located at a different location than
borehole 280-1 and located the radial distance 285 from the first
location 284. To achieve the same, the deck 230 of rig 200 can
pivot on turret 240 to drill borehole 280-2 while the drill rig 200
remains at the first location 284. As the reader will appreciate,
in various embodiments, the radial distance may vary if different
boreholes are drilled at different angles, e.g., if some boreholes
are drilled vertically and some at angles away from vertical.
[0045] Subsequent boreholes, e.g., 280-3, 280-4 . . . 280-N, can be
formed by repeating the above described sequence and methodology.
As mentioned above, in various embodiments, the drilling rig can be
configured such that the erectable mast of rig can remain in a
vertical erected position while the deck rotates. That is, in
various embodiments, borehole drilling operations subsequent to a
first borehole drilling operation can be performed without fully
having to move the vertical orientation of the erectable mast after
drilling a first borehole. As the reader will appreciate, the
erectable mast may be partially lowered to achieve angled drilling
operations as described in connection with FIG. 3. In such
embodiments, the deck can rotate while the erectable mast is in the
partially lowered position in order to perform subsequent angled
borehole drilling operations.
[0046] Although specific embodiments have been illustrated and
described herein, those of ordinary skill in the art will
appreciate that an arrangement calculated to achieve the same
results can be substituted for the specific embodiments shown. This
disclosure is intended to cover adaptations or variations of
various embodiments of the present disclosure. It is to be
understood that the above description has been made in an
illustrative fashion, and not a restrictive one. Combination of the
above embodiments, and other embodiments not specifically described
herein will be apparent to those of skill in the art upon reviewing
the above description.
[0047] The scope of the various embodiments of the present
disclosure includes other applications in which the above
structures and methods are used. Therefore, the scope of various
embodiments of the present disclosure should be determined with
reference to the appended claims, along with the full range of
equivalents to which such claims are entitled. In the foregoing
Detailed Description, various features are grouped together in a
single embodiment for the purpose of streamlining the disclosure.
This method of disclosure is not to be interpreted as reflecting an
intention that the disclosed embodiments of the present disclosure
have to use more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter
lies in less than all features of a single disclosed embodiment.
Thus, the following claims are hereby incorporated into the
Detailed Description, with each claim standing on its own as a
separate embodiment.
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